1. Field of the Invention
The present invention relates to pottery and glass kilns, and, in particular, to an improvement that allows for quick removal and replacement of the hard ceramic holder that is used for holding the wound electrical heating element within the kiln.
2. Description of the Prior Art
Pottery and glass kilns, typically of insulating brick, utilize electrical elements that are wound coils made of special metal alloys for heating.
These heating elements have traditionally been placed and held in position in channels located in the interior wall of the kiln.
The heating elements are wound like a spring and then stretched to fit into the length of a designated channel around the inner circumference or perimeter of the kiln's interior wall.
These channels are formed by routing a groove with a retaining lip into the kiln's brick to allow entry of the heating element into the wall of the kiln. Once in position, the heating element is retained by a fragile brick vertical lip and pressing or pinning the element in place to prevent it from jumping back into the interior chamber of the kiln.
Heating elements have also been held in place in hard ceramic extruded holders that are embedded permanently into the softer insulating brick and not readily changed.
A problem with both of these prior art heating element retention systems where the elements are held in channels is that the heating elements can fuse into the soft insulating brick or the hard ceramic holder due to over-firing, or electrical arcing, thus melting the element into the brick or ceramic holder.
Another problem occurs when ceramic glaze accidentally lands on the heating element and holder which then melts and fuses the heating element into the holder. Once element and holder become fused, it is very difficult to repair. The soft brick melts away and breaks down with the fusion. Thus, removing the damaged element removes sections of the soft brick which cannot be repaired. This compromises the ability of the replacement element to stay in its position in the channel.
Additionally, hard ceramic element holders which become fused to the heating element cannot be removed from the kiln and removing just the heating element from the channel is extremely time consuming and difficult.
Both type heating element retention systems that have been damaged are difficult, if not impossible to decontaminate of glaze spills or burnout of the brick. As a result, remaining debris from a glaze accident, by over-firing, melt down and can contaminate a replacement heating element causing it to fail prematurely. The heating elements are expensive, so premature loss due to contamination within a channel is very expensive.
Traditionally, the only recourse the operator has had to fix this type of damage required dismantling of the entire kiln, which is time consuming, expensive and beyond the technical ability of most users of such a product.
It is towards a solution to these problems that the present invention is directed.